Solvay and partners Wyeth and Lundbeck have presented clinical study results which could push their experimental antipsychotic bifeprunox closer to approval.

In a Phase III study, bifeprunox demonstrated its ability to maintained stability in patients with stable schizophrenia over a period of six months. Furthermore, in six-week trials, patients with acute exacerbations of schizophrenia taking bifeprunox experienced an improvement in symptoms compared to the placebo group. But the drug showed a “smaller mean effect” than existing treatments compared to placebo, the groups noted.

However, bifeprunox did show a favourable weight and metabolic profile in both short- and long-term studies versus placebo or active references, and Professor Daniel Casey at Oregon Health and Science University said that, based

on the data, “if approved, bifeprunox may be a valuable treatment option for stable patients with schizophrenia.”

He added that these are “important new findings because some obstacles, including side effects associated with current treatments, can derail the optimal long-term care of patients with schizophrenia.”

Wyeth and Solvay filed bifeprunox with the US Food and Drug Administration in October and, if approved, Wyeth says annual sales could reach $1 billion. However, last year, Lundbeck delayed filing for approval of the treatment in Europe until 2008 as it carries out additional Phase III testing.